Re: Back up to CD-R

[Ben Liberman]

>At 16.08 -0500 2000-01-02, Ben Liberman wrote/2000-01-02, 16.08 
>-0500 skrev Ben Liberman:
>
>>Retrospect will only work with CD-R's that support packet writes.
>>With packet writing you can burn 56k packets (if I recall correctly)
>>and the backup is done as a series of small writes with no real-time
>>constraints - it can be started and stopped, packet by packet, all
>>along the way.
>
>Why doesn't Toast work this way?
>And if my CD-burner supported Retro writeing CD-RW:s is that a sign 
>that it supports "packet writing"?

To answer your second question is Yes.

As for your first question - the short answer is that is wastes space.

There are several industry standards that relate to CD's.

Andy McFadden's CD-Recordable FAQ is very good and is updated monthly
and I'm fairly certain that all the questions that you can think of
will be better answered there than by me.

   http://www.fadden.com/cdrfaq/

---

Also here is a quote from

http://www.sanyo-verbatim.com/news/bulletins/packet_written_cdr.htm

"Packet writing allows the user to write very small amounts of data
at a time. Every time data is written it also creates "link blocks".
This is what the CD-R uses to link between recorded area and the next
area to be recorded. These link blocks create errors (and consequently,
problems) when trying to read continuously, as in a mastering application."

---

The Orange Book standard defines CD-Recordable discs with 
multisession capability.

Part   FormatVersion  Date Comments
 I CD-MO -   Nov 1990  Magneto Optical re-writable discs
 II CD-R   3.1   Dec 1998  was CD-WO - Write Once
 III   CD-RW   1.95  May 1998  ReWritable


  All three parts contain the following sections:

 Disc specification for unrecorded and recorded discs.
 Pre-groove modulation .
 Data organization including linking.
 Multisession and hybrid discs
 Recommendations for measurement of reflectivity, power control etc

---

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  [EMAIL PROTECTED]  Ben Liberman
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Re: Back up to CD-R

[david bonde]

At 16.08 -0500 2000-01-02, Ben Liberman wrote/2000-01-02, 16.08 -0500 
skrev Ben Liberman:

>Retrospect will only work with CD-R's that support packet writes.
>With packet writing you can burn 56k packets (if I recall correctly)
>and the backup is done as a series of small writes with no real-time
>constraints - it can be started and stopped, packet by packet, all
>along the way.

Why doesn't Toast work this way? And if my CD-burner supported Retro 
writeing CD-RW:s is that a sign that it supports "packet writing"?



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Re: Back up to CD-R

[Ben Liberman]

>I plan to switch from CD-RW to CD-r as my backup media for my home 
>network (2-3 machines on a 10Mbit hub). However, burning CD:s with 
>Toast is a very sensitive process, how does Retrospect handle lag in 
>the network and other problems that can occur?
>
>
>Fact about my net: my "server" will be a Umax clone with 112MB RAM 
>and a 603e@200HMz, and my clients are a G4/400, maybe a Powerbook 
>520 and if possible a Sun Sparc IPX (can I do something with FTP 
>with this machine?).

With toast the minimum burn is aprox. 10 megabytes and the communications
between the machine and burner can't lag past the amount of time it takes
to empty the buffer on the burner.  Since the Mac is not a real-time machine,
if there is enough other activity going on, Toast won't be able to keep the
writers buffer from emptying.

Retrospect will only work with CD-R's that support packet writes.
With packet writing you can burn 56k packets (if I recall correctly)
and the backup is done as a series of small writes with no real-time
constraints - it can be started and stopped, packet by packet, all
along the way.

--
  [EMAIL PROTECTED]  Ben Liberman
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